But people who have already received one AstraZeneca dose can't get a different second jab because Australia has not approved mixing vaccines.

It follows federal changes opening Pfizer and Moderna to everyone aged 12 and older.

More than 95 per cent of ACT residents aged 50 and over are already partially vaccinated, with nearly 87 per cent double-dosed.

Chief Minister Andrew Barr wants people to bring forward their bookings to speed up the vaccination process before lockdown ends at 11.59pm on October 14.

"There are earlier appointments available and we are very keen to give everyone the opportunity to get at least a first dose before we come out of lockdown in the middle of October," he told reporters.

"All of the vaccines are good, safe and effective. The bottom line is the people who are most at risk, particularly adults, they're going to be the unvaccinated."

Meanwhile, 17 cases were linked to known cases or ongoing clusters. At least that number were also in the community while infectious, with six in quarantine the whole time.

Businesses will be eligible for extra financial support, funded 50-50 by territory and federal governments, to help get them through until mid-October.

The ACT expects its vaccination rate to hit 80 per cent at that point.

The latest federal data shows more than 63 per cent of over-16s are double-dosed while 90 per cent have had one jab.

Slightly more than half of ACT children aged between 12 and 15 have had their first dose.

The territory is working through how any vaccine mandates for parts of the public service, apart from aged care where vaccination is already required, would work.

The aged care worker mandate is national and came into effect earlier this month.

There are 246 active cases in the ACT, 10 of them in hospital including three people in intensive care requiring ventilation.

Total business support applications approved since the start of the lockdown were expected to reach nearly 5400 - valued at around $85 million - on Thursday.

Another 759 applications needed more information and 1407 had been partially assessed.

Under the revamped support plan, a grant of $10,000 for all employing small businesses, and $3750 for non-employing businesses, will be paid to those who were eligible for the COVID-19 Business Support Grant in industries still significantly impacted by health restrictions.

A top-up payment will also be made available to large businesses.

A program to help tourism, events, hospitality, fitness and dance businesses will offer $5000 for non-employing businesses, rising to $25,000 for businesses with turnover greater than $5 million.

Australian Associated Press